Musannaf Ibn Abi Shayba 9:834

'Abdah narrated to us, from Sa'id, from Qatadah, from al-Hasan, from Zayd ibn Thabit and al-Zubayr ibn al-'Awwam: They used to see no harm if a man divorced his wife, while she was a slave-girl, two pronouncements, then her master had intercourse with her—an act of intercourse not intending by that deception nor to make her lawful [for the husband]—that she may return to her husband by him proposing to her.